"The (European) Commission has indeed sent requests for information to Apple and Samsung concerning the enforcement of standards-essential patents in the mobile telephony sector," it said in a statement.

Keen to stress that requests for such information are "standard procedure", Apple's filings suggest a deeper investigation into Samsung's patent claims.

In retaliation for Apple's assault, Samsung's counterclaims are based upon patents essential to UMTS, a crucial technology enabling 3G cellular transmissions across mobile networks. These patents were licensed under "Fair, Reasonable and Non-Discriminatory" (FRAND) terms, which Apple argues is bad for business and a breach of Samsung's pledge.

"Samsung's litigation campaign and other conduct related to its declared-essential patents is so egregious that the European Commission recently has opened an investigation to determine whether Samsung's behaviour violates EU competition laws."

Samsung told a Dutch publication that it is co-operating fully with the authorities.

If the Commission finds that Samsung has broken antitrust law, it could result in Samsung being forced to drop its legal cases against Apple in Europe, which could then in turn trickle down to remaining, ongoing action in other non-EU jurisdiction.

The Commission can fine a company up to 10 percent of its global turnover, if European rules have been violated, reports Reuters.

Apple has argued that Samsung's Galaxy smartphones and tablets infringed Apple's design patents pertaining to its iPhone and iPad devices. Samsung, however, has returned fire by bringing its own patents infringement claims against the Cupertino-based giant, in a number of European courts.